Share-Based Compensation Stock Option Information Related to Equity Incentive Plan (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Options
Outstanding, beginning of period	2,060,413
Granted	313,472
Exercised	(796,101)
Forfeited	(62,672)
Expired	(953)
Outstanding, end of period	1,514,159
Vested and expected to vest, end of period	1,468,430
Exercisable, end of period	680,684
Weighted average exercise price
Outstanding, beginning of period	$ 49.15
Granted	$ 71.68
Exercised	$ 45.74
Forfeited	$ 57.18
Expired	$ 51.86
Outstanding, end of period	$ 55.27
Vested and expected to vest, end of period	$ 54.91
Exercisable, end of period	$ 44.50
Weighted Average Remaining Contractual Life in Years
Outstanding, end of period	4 years 3 months 7 days
Vested and expected to vest, end of period	4 years 2 months 23 days
Exercisable, end of period	3 years 4 days
Aggregate Intrinsic Value of In-The-Money Options
Outstanding, end of period	$ 75,092,637
Vested and expected to vest, end of period	73,347,808
Exercisable, end of period	$ 41,087,846